METERING REQUIREMENTS FOR INTERCONNECTION POINTS OF SERVICE

Transcription

1 METERING REQUIREMENTS FOR INTERCONNECTION POINTS OF SERVICE Author: AXLIU Origination Date: 05/07/2010 Version: 8.3 Revised By: Approver s Name: OXPAIS REROMAK REROMAK 1 PURPOSE Revision Date: 9/12/2016 Review By: 09/01/2017 Approver s Signature (If required by Std) Approval Date: 6/01/ To provide guidelines for SRP s requirements for revenue metering at the point(s) of interconnection with other entities. The revenue metering shall include the meter(s), associated current transformers (CTs) and voltage transformers (VTs), and any applicable associated equipment. 1.2 This document addresses compliance of NERC Standards and is posted on the OASIS website: Standard Requirement Description Effective Date BAL b R 12.3 Balancing Authorities shall install common metering equipment where Dynamic Schedules or Pseudo-Ties are implemented between two or more Balancing Authorities to deliver the output of Jointly Owned Units or to serve remote load. 5/13/ Requirements are defined in Section 5: Subsection Title Page 5.1 REVENUE METERS POLARITY STANDARD INSTRUMENT TRANSFORMERS METERING DATA TRANSFER & COLLECTION 6-7 Page 1 of 8

2 2 REFERENCES 2.1 IEEE Std. C IEEE Standard Requirements for Instrument Transformers 2.2 SRP Substation Construction Standard GS06.02 Instrument Transformers, Secondary Wire Designations 2.3 SRP Substation Construction Standard GS11.02 Instrument Transformer Schematic Diagram, Auxiliary Current and Potential Transformer Grounding 3 TERMS AND DEFINITIONS 3.1 CT: Current Transformer 3.2 VT: Voltage (Potential) Transformer 3.3 INSTRUMENT TRANSFORMERS: Current and voltage transformers that are associated with the revenue metering. 3.4 REVENUE METERING: All equipment involved to measure the power/energy flow and provide metering data. It shall include meter(s), current transformers, voltage transformers, communication path and protection equipment. 3.5 RTU: Remote Terminal Unit 3.6 SCADA: Supervisory Control And Data Acquisition 3.7 DNP: Distributed Network Protocol 3.8 CMS: Customer Metering Services to include Metering and Field Customer Services and Meter Engineering Support Page 2 of 8

3 4 RESPONSIBILITIES 4.1 Customer Metering Services (CMS) Provide guidance for Revenue Metering Requirements for Interconnection Metering. 1. Specify and approve metering equipment to be installed 2. Coordinate with other SRP groups and entities to provide required output data from the revenue meter(s) 3. Review and approve design of revenue metering circuits 4. Test and maintain revenue meters 5 REQUIREMENTS 5.1 REVENUE METERS Revenue grade metering equipment shall be required at each point of interconnection with the SRP system. 1. Depending on the expected load, meter(s) shall have a class 10 rating (accurate from A RMS) or a class 20 rating (accurate from A RMS) 2. Meters shall have a 0.3% or better accuracy rating 3. Meters shall be capable of measuring and providing additional parameters such as per phase quantities (i.e., volts, amps), frequency, etc. dependent on meter specifications and interconnection application requirements The revenue meter(s) shall consist of a single meter supplied and installed by either SRP or the interconnecting entity capable of measuring bidirectional, four quadrant watt and var parameters. 1. The point of revenue metering installation shall be at the point of interconnection between entities wherever possible. 2. If the point of interconnection or boundary is located at a remote point that prohibits feasible metering equipment installation, the metering equipment shall be installed at the closest practical point. Page 3 of 8

4 3. The meter shall be programmatically compensated to account for impedance and losses between the physical metering point and the defined interconnection/boundary point. If a meter is compensated, the compensation values and calculations will be reviewed and mutually agreed to between all interconnection entities In cases where backup metering is determined as a requirement, the backup meter can be added to the same set of CTs and VTs. Consult CMS for approval. 5.2 POLARITY STANDARD The metering diagram shown below in Figure 1 depicts the standard polarity position for CTs and metering interfaces as they relate to power providers and power consumers. If a need arises to reverse polarity due to provider and consumer reassignments, the meter(s) shall be able to do so by changing the parameters in the meter program. 1. When the current flows through the polarity side of the CTs, the meter shall register a positive (+) instantaneous value and a forward direction accumulator value. Accordingly, the meter shall register kwh delivered in the billing load profile. 2. Vice versa, when the current flows through the non polarity side of the CTs, the meter shall register a negative (-) instantaneous value and a reversed direction accumulator value. In such case, the meter shall register kwh received in the billing load profile. Figure 1 Page 4 of 8

5 5.2.2 It is important to note what constitutes power/energy flow in/out of SRP s Balancing Authority Area (BAA). Therefore the revenue meters and CTs shall be connected per following applications as depicted in Figure 2 shown below. 1. For SRP owned/operated Generation plant or Generation plant that is in SRP s BAAs. a. The revenue meter(s) and the CTs shall be connected such that the net generation at the plant would be measured as delivered and positive (+) power. The auxiliary power that is consumed by the plant would be measured as received and reverse(-) power. 2. For energy flow between BAAs, the connection manner below should apply. a. Energy flow into SRP BAAs from another BAA i. The revenue meter(s) and the CTs shall be connected such that the power/energy flow would be measured as received and reverse (-) power. ii. In such cases, the power/energy parameter in telemetry (i.e. in DNP) should show negative (-) and the kwh received would be registered in the billing load profile. b. Energy flow from SRP BAAs to another BAA i. The revenue meter(s) and the CTs shall be connected such that the power/energy flow would be measured as positive and forward (+) power. ii. In such case, the power/energy parameter in telemetry (ie. in DNP) should show positive (+) and the kwh delivered would be registered in the billing load profile. Figure 2 Page 5 of 8

6 5.3 INSTRUMENT TRANSFORMERS Instrument transformers shall be revenue grade with a rating of 0.3% accuracy or better at full load and 0.6% accuracy or better at light load. Burden specifications of instrument transformers shall meet or exceed the expected total burden ratings of connected revenue meters and other connected devices. Typical burden is B CTs shall have a primary current rating equal to the bus capacity where installed. Secondary current rating shall be 5 amperes at full primary current. 1. In applications where normal operating conditions will cause the primary current to be below the 10% light load rating, higher accuracy and extended range CTs will be required for accurate power measurement The secondary terminals of the CTs and VTs shall be connected only to revenue metering or other monitoring devices such as transducers. Exceptions for this requirement shall be mutually agreed upon between interconnecting entities. 5.4 METERING DATA TRANSFER & COLLECTION Revenue meter(s) installed at interconnection point(s) shall be accessible via phone line, Ethernet, or secured radio communications to retrieve hourly data for billing purposes. The number of telephone or ethernet circuits required will be determined and specified on a site by site basis Revenue meter(s) shall be able to provide measured power/energy parameters to the RTUs, other SCADA equipment, station computers, or other system control equipment through DNP and/or Modbus protocol. Typical data requirements are shown below: 1. Analog Points a. MW IN/OUT b. MVAR IN/OUT c. Net MW IN/OUT(for Generation Site) d. Net MVAR (Generation Site) e. Auxiliary MVAR (bi-directional) f. A Phase Amp g. PF h. Frequency Page 6 of 8

7 2. Accumulator Points or Digital pulse outputs a. Net MWh In/Out b. Net MVARh In/Out c. Auxiliary KWh (if applicable) Usage data registered by the interconnection revenue meter may be used for the following: 1. Automatic Generation Control/Power Dispatch Operation (AGC/PDO) 2. Transmission Generation Control (TGO) 3. Transmission related bill calculation Page 7 of 8

8 VERSION HISTORY Version Date Action Change Tracking Revised By 1 05/07/10 Created N/A Andrew Liu 2 11/10/11 Updated 3 08/06/12 Updated 4 03/08/13 Updated 5 08/08/13 Updated 6 9/11/13 Updated 7 11/11/13 Updated 8 8/12/14 Updated POLARITY STANDARD ADDED METERING DATA TRANSFER & COLLECTION TERMS AND DEFINITIONS POLARITY STANDARD METERING DATA TRANSFER & COLLECTION ADDED DESCRIPTION FOR STANDARD/REQUIREMENTS UPDATED STANDARD VERSION AND EFFECTIVE DATE UPDATED STANDARD VERSION AND EFFECTIVE DATE FOR FAC UPDATED FIGURE 1 IN SECTION AND UPDATED VERBAGE IN Andrew Liu James Statzer/ Rob Romak 8.1 8/10/15 Updated UPDATED VERBIAGE IN /6/2016 Updated UPDATED SECTION 1.2, UPDATED FIGURE 1 IN 5.2.1, AND ADDED FIGURE 2 IN /12/2016 Updated UPDATED DEFINITIONS Page 8 of 8